US6469526B1 - System for detecting conductive contaminants and method of use - Google Patents

Abstract

The present invention provides a system to detect conductive contaminants interspersed within unconsolidated materials. By using the system described herein, voluminous amounts of unconsolidated materials such as soils, waste streams, hay, and similar non-conductive materials may be processed such that conductive contaminants, namely metal objects, may be identified and removed from the processed material. In general, the present invention utilizes the conductive property of these contaminants to alert the system such that the contaminant may be removed. By passing the unconsolidated materials across an arrangement of different contacts placed in close proximity, metal or similar conductive contaminants will complete an electrical circuit that signals a sensor within the circuit and initiates a partial shut down procedure. Though this sensor is preferably at least one programmable voltage sensor, the sensor may comprise a current transformer or light incorporated into the electrical circuit that detects each conductive contaminant. A light sensor that may trigger at least one relay to halt the processing of material as described herein may detect this emission. This system and its method of use may be adapted to detect conductive contaminants in voluminous, unconsolidated materials in a variety of applications.

Description

FIELD OF THE INVENTION

This invention relates to a system for detecting conductive contaminants interspersed within unconsolidated, primarily non-conductive materials. The conductive properties of the contaminants complete a detectable electrical circuit. In addition, a method of using this system allows for the removal of potentially dangerous or harmful conductive contaminants from the unconsolidated materials.

BACKGROUND OF THE INVENTION

Waste recycling companies and waste management companies have searched for new technology to detect and remove harmful conductive contaminants interspersed within nonconductive, unconsolidated materials. For example, nails, aluminum cans, and metal refuse are often discarded in composts, soils, or waste materials. Likewise, hypodermic needles, razors, or similar potentially hazardous contaminants may also be discarded within these unconsolidated materials. As such, it is preferably to remove these contaminants before the waste materials are recycled to provide source materials for potting soils, fertilizers, and other similar useful products.

Unfortunately, and despite the waste-recycling companies' best intentions, these now-useful materials occasionally include portions or remnants of these harmful and dangerous conductive contaminants. Due to the volume of unconsolidated materials that must be scrutinized for these conductive contaminants, it has been admittedly difficult to screen or search for these conductive contaminants. Countless tons of unconsolidated materials have not been recycled out of fear that conductive contaminants remaining therein could harm or otherwise injure those attempting to use these recycled materials.

In fact, recycled materials that contain conductive contaminants have harmed innocent users. For example, purchasers of these recycled materials have risked the danger of being harmed by nails, cans, or similar items that were interspersed within these unconsolidated materials. In an extremely dangerous situation, it is conceivable that users of these recycled products could encounter a discarded hypodermic needle that could be contaminated with an infectious disease.

Waste recycling companies have devised or used various methods of detecting these conductive contaminants with marginal success. For example, it is possible to visually inspect small amounts of unconsolidated material for these kinds of conductive contaminants. Due to the nature of the unconsolidated materials and the size of the conductive contaminant, however, this type of search is literally “looking for a needle in a hay stack.” Due to the excessive volume of materials that must be screened, a visual inspection is impractical and inefficient.

In the alternative, the prior art described sifting techniques that would capture larger objects while allowing granules such as sand to pass through a sifter or a series of sifters. This method is particularly inappropriate when the unconsolidated material comprises branches, twigs, or similar structured materials that cannot pass through the relatively small holes of the sifters. Moreover, a strategically placed needle or similar conductive contaminant could theoretically pass through the sifting screens without being detected or removed.

Therefore, a serious need exists to provide a system and a method of using this system that can manage the voluminous amounts of unconsolidated materials that must be screened for these conductive contaminants such as nails and needles.

SUMMARY OF THE INVENTION

The present invention provides a system to detect the conductive contaminants interspersed within unconsolidated materials. By using the system described herein, voluminous amounts of unconsolidated materials such as soils, waste streams, hay, and similar non-conductive materials may be processed such that conductive contaminants, namely metal objects, may be identified and removed from the processed material.

Though many variations of the present invention will be evident to those skilled in the art, the present invention utilizes the conductive property of these contaminants to alert the system such that the contaminant may be removed. By passing the unconsolidated waste materials across an arrangement of alternatingly charged contacts placed in close proximity, metal or similarly conductive contaminants will complete an electrical circuit that may be detected by a sensor that alerts or otherwise indicates the presence of the conductive contaminant and initiates a shut down procedure.

In an alternative embodiment of the invention, this alerting system comprises a neon light incorporated into the electrical circuit that emits light when the circuit is completed by the conductive contaminant. When a light detector detects the emission of light, it triggers a relay to halt the processing of material as described herein. This system and its method of use may be adapted to detect conductive contaminants in voluminous, unconsolidated materials for a variety of applications.

The foregoing has outlined rather broadly the features of the system and method of the present invention so that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. Those skilled in the art should appreciate that the conception and the specific embodiments disclosed may be readily used as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form part of the specification, illustrate the embodiments of the present invention, and, together with the description, serve to explain the principles of the invention. In the drawings:

FIG. 1 an exploded perspective view of a preferred embodiment of the invention;

FIG. 2 is a close schematic front view of the internal assembly of an embodiment of the invention;

FIG. 3A is a schematic bottom view of the electrical connections of an embodiment of the invention;

FIG. 3B is a schematic bottom view of the electrical connections of an embodiment of the invention;

FIG. 3C is a schematic bottom view of the electrical connections of an embodiment of the invention;

FIG. 4 block diagram of an alternative embodiment of the detection circuit of the invention;

FIG. 5 is a side view showing a close up of a section comprising a conductive contaminant;

FIG. 6 is a block diagram of a preferred method of forming the detection circuit of the present invention; and

FIG. 7 is a schematic bottom view of the electrical connections of another embodiment of the invention.

It is to be noted that the drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention will admit to other equally effective embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Though many methods of conveying unconsolidated waste material will be evident to those skilled in the art, the preferred embodiment of the invention as shown in FIG. 1 comprises a plurality ofconveyors10 and11, preferably about 24 inches (61 cm) wide, as described herein as in-feed conveyor10 and discharge conveyor11. Unconsolidated material is transported up the in-feed conveyor10 such that the unconsolidated material is deposited intoinfeed hopper12. With proper positioning of infeedhopper12, unconsolidated material is ultimately disposed upon detectingwheel15 for maximum efficiency in detecting any conductive contaminants contained therein. Asdetection wheel15 rotates, the unconsolidated material now verified to be devoid of conductive contaminants, is collected inhopper13 and ultimately falls upon discharge conveyor11 to be transported or packaged for future use.

Eitherhopper12 or13 typically comprises a top opening16 and bottom opening17, wherein the bottom opening17 is slightly smaller in area than top opening16. The positioning ofhopper12 may be adjusted, preferably on metal rails, to strategically deposit or channel unconsolidated material ondetection wheel15 such thatdetection wheel15 may handle the flow of unconsolidated material quickly and efficiently. In the preferred embodiment, thebottom opening17 of the hopper comprises approximately 20 inches (50.8 cm)×42 inches (106.7 cm) and thedetection wheel15 is about 36 inches (91.4 cm) along its axis.

Hopper12 is preferably movably attached toframe assembly14 such thathopper12 is adjustably disposed to deposit unconsolidated material, possibly comprising conductive contaminants, ondetection wheel15 in an optimum location for the detection of the conductive contaminants. Although those skilled in the art will recognize variations to this positioning, the preferred embodiment comprises at least 2 inches (5.1 cm) of clearance between the bottom opening17 ofhopper12 and the closest point of rotation ofdetection wheel15 during a complete rotation cycle.

In the preferred embodiment, thedetection wheel15 is moved or controlled by a variable speed gearbox andmotor18 capable of operating from about 7 rotations per minute (“RPM”) to about 75 RPM, more preferably 20 RPM to 25 RPM. The motor is preferably a three-phase, one-horsepower electric motor operating at 220 volts. This gear box andmotor18 is rotatably attached via a belt, chain, orsimilar drive19 to arotatable shaft20 that extends through the axis ofdetection wheel15.

As shown in FIG. 2,shaft20 preferably comprises a 3{fraction (7/16)} inches (8.73 cm) tube shaft resting upon a plurality of 3{fraction (7/16)} inches (8.73 cm)pillow block bearings21aand21bdisposed about either end ofshaft20 to provide a requisite load bearing member capable of sustaining thedetection wheel15 while allowing for the necessary wiring discussed below.

In addition, at least one support disk, shown as a pair ofsupport disks26aand26bin FIG. 2, may be fixedly attached to theshaft20. Thesedisks26aand26bpreferably have a diameter of about 36 inches (91.4 cm) and have anouter rim26cand26d, respectively, to provide the requisite support and attachment forsections25a,25b,25c,25d,25e, and25f(referred to as25a-25fherein) of thedetection wheel15 shown in FIG.1. Though many configurations will be evident to those skilled in the art, eachsection25a-25fofdetection wheel15 may be fixedly attached to the outside of eachdisk26aand26bsuch that eachsection25a-25fis disposed in a hexagonal configuration to form thedetection wheel15. The hexagonal prism configuration ofsections25a-25fforms the exterior surface ofdetection wheel15 that is but one embodiment of thedetection wheel15. Those skilled in the art will recognize thatdetection wheel15 may be formed of any plurality of surfaces or even one continuous cylindrical surface such thatdetection wheel15 would resemble a cylinder. Accordingly, any number ofsections25 could be attached to one ormore support disks26aand26bto formdetection wheel15.

Preferably sixsections25a-25fare arranged to form a hexagonal prism shapeddetection wheel15, as shown in FIG. 1, made of a variety of non-conductive materials. The revolvinghexagon detection wheel15 is controlled by variable speed motor andgear box18 attached thereto to enable the user to adjust the rotational speed according to the nature and density of the materials being processed. The operation of the speed motor andgearbox18 may be controlled by a simple on/off switch, lengthy cable apparatus, or remote control, all with appropriate emergency shut off devices.

As shown in FIG. 1, a plurality ofcontacts30 are arranged to protrude through an exterior surface of eachsection25a-25f. Though the arrangement will be discussed in more detail herein, no more than about ¾ inches (1.9 cm) may exist between each first contact and a second contact. In the preferred embodiment, eachsection25a-25fis about 12 inches (30.5 cm) wide, about 36 inches (91.4 cm) long, and about one inch (2.54 cm) thick.

Referring now to FIG. 3A, there is shown a schematic bottom view of the electrical connections of a preferred embodiment of the invention. More specifically, FIG. 3A shows a schematic representation of the contacts and bus bar relationships forrepresentative section25a. Those skilled in the art will recognize that significant variations of the contact positioning and electrical wiring as disclosed herein may be implemented.Representative section25aofdetection wheel15 comprises staggered rows ofcontacts31a,31b,31c,31d,31e,31f,31g,31h,31i,31j, and31k(referred to as31a-31kherein) such that alternating rows of contacts31a-31kbear a positive, defined as first contacts, and negative charge, defined as second contacts, respectively. By arranging these contacts31a-31kin staggered rows, conductive contaminants cannot be positioned such that they will not complete a circuit and signal the sensor system discussed herein. In the preferred embodiment, eachsection25a-25fcomprises 11 rows of contacts31a-31kand 36 columns ofcontacts32a-32jjalternating between first contacts and second contacts, respectively. Moreover, eachcontact30 is about 3 inches (7.62 cm) in length and made of a conductive material such as at least one metal that may convey a completed circuit in the presence of a conductive contaminant at thecontacts30 protruding throughsections25a-25f. Those skilled in the art will recognize the importance of selecting a conductive substance that is durable and can withstand the constant interaction and vibrations associated with the operation ofwheel15 with consolidated materials during normal operation. Those skilled in the art will also realize that the arrangement of wiring may reverse the charge or voltage available at the first contacts to be positive and the charge available at the second contacts to be negative.

The invention as described and claimed herein is intended to embody both directions of current. In other words, the contacts as defined as first contacts and second contacts, regardless of the electrical connections thereto, may be rearranged in any manner as long as conductive contaminants will fall within about ¼ inches (0.64 cm) to a first contact and within about ¼ inches (0.64 cm) to a second contact.

Each row of contacts31a-31kis connected by eleven longitudinal bus bars33a-33kdisposed along the length of eachsection25a-25f. Two latitudinal bus bars34aand34bare disposed at each end of eachsection25a-25f.Bus bar34aconnects alternating longitudinal bus bars32b,32d,32f,32h, and32j. Bus bar34bconnects alternatinglongitudinal bars32a,32c,32e,32g,32i, and32k.

Each of thesections25b-25fare similarly connected such that thecontacts30 are arranged in the staggered positioning as shown in FIG.3A and are electrically connected via the longitudinal bus bar and latitudinal bus bar arrangement depicted in FIG.3A. Of particular note,section25dis wired exactly the same assection25adepicted in FIG.3A.

Referring to FIG. 3B,sections25band25eare analogously connected such that the longitudinal bus bars connected tobus bar34aremain the same as depicted in FIG. 3A, however, longitudinal bus bars31a,31c,31e,31g,31i, and31kare connected to bus bar34C. Analogously,sections25cand25fare connected as depicted in FIG.3C. As with FIG. 3c, bus bar34 connects to the same longitudinal bus bars.Bus bar34d, however, connects to longitudinal bus bars31a,31c,31e,31g,31i, and31k.

Moreover, in the preferred embodiment, opposingsections25aand25d, are electrically connected to one another via electric brushes28a-28dthat are rotatably disposed about a plurality of conduction disks27a-28daffixed toshaft20 as shown in FIG.2. In this arrangement, bus bars34a-34dremain in constant and isolated electric communication with conduction disks27a-27d, respectively, via brushes28a-28d. Three conduction disks27b-27dprovide positive electrical charge to opposingsections25aand25d,25band25e, and25cand25f, respectively, and provide positive electric charge to all sixsections25a-25fofdetection wheel15 in aggregate. Additionally,bus bar34aremains in constant and isolated electrical communication withconductive ring27avia rotatably disposed brushes28ain the same fashion as the conduction disks27b-27d. In this configuration, each of the three conductive rings27b-27dand theconductive ring27aare attached torotatable shaft20 such that theconductive ring27ais insulated from the three conductive rings27b-27d. In a preferred embodiment, 2,4000 volts at 10 amps is provided at each positive conductive rings27b-27das explained below.

Each conduction disk27a-27dmay be electrically connected as depicted by the block diagram in FIG.4. As shown, each conductive ring27a-27dis electrically connected to an emission source or current sensing device, preferably a current transformer, most preferably an about 25 amp.current transformer45. Various emission sources that project emissions in the infrared, ultraviolet, and normal light spectrums are within the scope of this emission provided that each emission source chosen can withstand the surge of about 4,000 volts presented during a completed circuit. Also emissions sources ranging from sound emitters to emitters of electric signals or pulses could be detectable and could also be used. Conduction disks27b-27dare separately connected to threediscrete transformers46b-46dvia wiring or other means known to those skilled in the art. Eachtransformer46b-46dis in turn connected to the opposite pole of the emission source or current sensing device.

Upon completion of the circuit by a conductive contaminant at thecontacts30 as explained below, a discharge will course throughconductive ring27avia wiring inshaft20 to current transformer, most preferably an about 25 amp.current transformer45 electrically connected to negativeconductive ring27a.Current transformers45 are customarily operated at 10 amps so the voltage of the circuit does not present a problem. As explained,current transformer45 is electrically connected to eachtransformer46b-46d.Transformers46b-46dare preferably Ray-O-Vac™ transformers controlled by Veriack™ voltage reducers. Preferably,transformers46b-46dare used such that eachtransformer46b-46dis electrically connected to one of the positive conductive rings27b-27dvia the requisite wiring disposed within theshaft20. When the circuit is completed by an electrically conductive contaminant, as explained below,current transformer45 may control or suspend power to discharge conveyor11 and in-feed conveyor10.

As shown in FIG. 5, the preferred embodiment comprisesconductive contacts30 that extend at least about 2 inches (5.1 cm) from thesurface sections25a-25fofdetection wheel15. In this configuration,unconsolidated material50 drops upon the exterior surface ofdetection section25a, for example. The in-feed conveyor10 controls the feed ofunconsolidated material50 such that no more than about ½ inch (1.27 cm) ofunconsolidated material50 collects upon thecontacts30. This configuration insures thatunconsolidated material50 that may comprise wood, twigs, or other semi-rigid, structured contents are not upwardly disposed such that aconductive contaminant51 could be positioned beyond the top ofcontacts30.

Theconductive contaminant51 strikes a first contact,30afor example, fromrows32b,32d,32f,32h, or32j, and second contact,30bfor example, fromrows32a,32c,32e,32g,32i, or32k, to create the circuit. Due to the 2,400 volts available at eachcontact30, a physical strike is not necessary. Proximity of thecontaminant51 within about ¼ inch (0.64 cm) of thecontact30 is all that is needed for the circuit to form. The completion of the circuit causescurrent transformers45 to flash. Whencurrent transformers45 activate power shut offrelay47, as shown in FIG. 4,conveyors10 and11 may stop. Onceconveyors10 and11 shut down,detection wheel15 continues to rotate, expelling the conductive contaminant, along with the unconsolidated material, onto discharge conveyor11.

This breaks the completed circuit and, after a period necessary forwheel15 to expel all material comprising the aforementioned outgoing conveyor11, laden with unconsolidated material that contains some conductive contaminant, is wiped by a delayedwiper48 shown in FIG. 1 that disposes of the unconsolidated material containing the conductive contaminant. Once the discharge conveyor11 has been wiped, the in-feed conveyor10 and discharge conveyor11 are reactivated, either automatically or by using a manual reset button (not shown). The material wiped or manually removed that may comprise a conductive contaminant may be safely disposed. Moreover, it is envisioned that discharge conveyor11 could be rotated and the materials could be ushered to a second receptacle (not shown).

Of note, the voltage of the system can be adjusted to change the charge available atcontacts30. Depending on the moisture level of the unconsolidated material, the amount of voltage may need to be reduced in order to prevent false readings due to the conductive nature of the moisture content in the unconsolidated material. The metal detection system is adjustable in several ways.

First, the rate of material may be controlled by the speed of theconveyors10 and11. The accumulation of unconsolidated materials on thesections25a-25fshould only be about ½ inches (1.27 cm) in height in comparison to the 2 inches (5.1 cm) of exposedcontacts30. This arrangement protects against a conductive contaminant from being unnoticed because it was above the top of thecontacts30. Increasing the speed ofconveyor belt10 will pour more consolidated material intohopper12. Second,hopper12 may be positioned such that the unconsolidated material being filtered throughhopper12 is deposited upon thedetection wheel15 at an optimum position. Third, the voltage via thetransformers46b-46dmay be adjusted to provide for a voltage setting that will reduce the false detections when unconsolidated material comprises a moisture content that would otherwise create false readings by short circuiting the system. In this situation, voltage is reduced to no less than about 1,000 volts. As the voltage is reduced, however, the sensitivity of thedetectors48 orcurrent transformers45 must be adjusted to recognize a more faint signals when the circuit is completed by a conductive contaminant. Fourth, the rotation speed of thedetection wheel15 may be adjusted to optimize the load conditions of the unconsolidated material being detected.

In another embodiment of the present invention, anair manifold49, as shown in FIG. 1, can be disposed such that it may dislodge unconsolidated material intertwined within thecontacts30 whendetection wheel15 rotates thatsection25a-25fto an unloading position. In addition, some conductive contaminants may become “welded” to opposingcontacts30aand30b, for example, as a result of the current passing through the circuit.Air manifold49 is capable of producing a dislodging air gust capable of freeing the conductive contaminant from this arc-welded situation.

Moreover, the present system for conductive contaminants and its method of use may preferably comprise a system that omits the emission source and detection relay system as previously disclosed. As shown in FIG. 6, a block diagram of the preferred embodiment of the system, eachpositive contact30 is electrically connected viashaft20 to positive conductive ring61aand eachnegative contact30 is electrically connected to negative conductive ring61b. Negative conductive ring61bis electrically connected to boosttransformer62 such that about 2,400 volts and about two amps are available at all times. This is accomplished byboost transformer62 receiving an input voltage of about 220 volts at about 42 amps, depicted byinput lines62aand62b, such thatboost transformer62 raises the voltage to about 2,400 volts while reducing the amperage to 2 amps. Boosttransformer62 receives its power from typical 220-volt sources of power (not shown) viainput lines62aand62bknown to those skilled in the art. This combination of voltage and amperage creates the potential of electricity needed for the detection of conductive material in the compost or waste material.

As seen in FIG. 6, the positive terminal ofboost transformer62 is electrically connected toprogrammable voltage sensor63. Thissensor63 monitors the amount of voltage leaving conductive ring61a. When the circuit is completed, presumably by a conductive contaminant atcontacts30, the change in electrical charge will be sensed byprogrammable voltage sensor63.Sensor63 will then send a signal to relay64 that will stop the detection system process as previously described. Conductive ring61ais also electrically connected to spark gap switch65. Spark gap switch65 is a switch turned by anelectric motor69. Though many variations will be evident to those skilled in the art, switch65 may comprise a sparkgap switch tip65athat is turned by themotor69 such thatarm65acomes into an electrical contact with a plurality of pins66a-66l.

Those skilled in the art will recognize the variations on the number of pins66a-66land the electrical communication withcontacts30 may be varied significantly without exceeding the scope of the present invention. As depicted, FIG. 6 shows12 pins66a-66larranged in a dodecagon or circular configuration such that the switch65 may be rotated to cause the sparkgap switch tip65ato form a circular path that electrically connects with each pin66a-66l, in turn. In this configuration, switch65 may be rotated at about 360 RPM. This rotation allows for switch65, namely tip65a, to be in electrical communication with each pin66a-66lapproximately 3.6 times per second.

In turn, each pin66a-66lis electrically connected to a bus bar67a-67l. As shown, pin66ais electrically connected tobus bar67a. Accordingly, pin66bis in electrical communication tobus bar67b. Respectively, pins66c-66lare similarly connected to bus bars67c-67l. When spark gap switch65 contacts to each pin66a-66l, the connection will provide about 2,400 volts at each bus bar67a-67lfor this brief, but cyclical period of time. As arranged, the rotation of the sparkgap switch tip65ainsures that each bus bar67a-67lreceives this available charge about 3.6 times per second.

Moreover, as shown in FIG. 6, a secondprogrammable voltage sensor68 is in electrical communication with the input lines62aand62boftransformer62. Thisvoltage sensor68 functions similarly toprogrammable sensor63 such that if a change in electrical charge is sensed ininput lines62aand62bdue to a conductive contaminant forming a complete circuit in the system,programmable voltage sensor68 will send a signal to relay64 that will shut down the system as previously described. Though the redundancy in theprogrammable voltage sensors63 and68 is optional, those skilled in the art will recognize that asecond voltage sensor68 provides an additional level of detection and insurance that conductive contaminants will be properly detected and removed from the unconsolidated material.

As shown, spark gap switch65 may be rotated bymotor69 either by direct shaft or similar drive mechanism69d.Motor69 is electrically connected via conductive rings61cand61dto a 110-volt power source known to those skilled in the art (not shown) and is electrically connected via input lines69aand69b. Accordingly,motor69 is preferably a 110-volt motor capable of consistently rotating spark gap switch65 at 360 RPM.

FIG. 7 is a schematic bottom view of the electrical connections of a preferred embodiment of the invention. More specifically, FIG. 7 shows a schematic representation of the contacts and bus bar relationships forrepresentative section25a. Those skilled in the art will recognize that significant variations of the contact positioning and electrical wiring as disclosed herein may be implemented.Representative section25aofdetection wheel15 comprises staggeredcontacts30 such that alternating rows of contacts31a-31kbear a positive, defined as first contacts, and negative charge, defined as second contacts, respectively. By arranging these contacts31a-31kin staggered rows, conductive contaminants cannot be positioned such that they will not complete a circuit and signal the sensor system discussed herein. In the preferred embodiment, eachsection25a-25fcomprises about 11 rows of contacts31a-31kand about 36 columns ofcontacts32a-32jjalternating between first contacts and second contacts, respectively. As before, eachcontact30 is about 3 inches (7.62 cm) in length.

Those skilled in the art will realize that the arrangement of wiring may reverse the charge or voltage available at the first contacts to be positive and the charge available at the second contacts to be negative. The invention as described and claimed herein is intended to embody both directions of current. In other words, the contacts as defined as first contacts and second contacts, regardless of the electrical connections thereto, may be rearranged in my manner as long as conductive contaminants will fall within about ¼ inches (0.64 cm) to a first contact and within about ¼ inches (0.64 cm) to a second contact.

As shown,rows31b,31d,31f,31h, and31jofcontacts30 are electrically connected to one another via longitudinally disposedbus bars33b,33d,33f,33h, and33j, respectively, which in turn are connected tobus bar34aas previously described in this invention.Rows31a,31c,31e,31g,31i, and31kofcontacts30 are similarly electrically connected to theother contacts30 via longitudinally disposedbus bars33a,33c,33e,33g,33i, and33k, respectively. However, bus bars33a,33c, and33econnect tobus bar67a. Similarly, bus bars33g,33i, and33kconnect tobus bar67b. When spark gap switch65, shown in FIG. 6, provides an electrical path via pin66atobus bar67a, this arrangement will provide an available charge atbus bars33a,33c, and33eand thecontacts30 contained onrows31a,31c, and31e. Subsequently, when spark gap switch65 provides an electrical path via pin66btobus bar67b, this arrangement will provide an available charge at bus bars33g,33i, and33kand thecontacts30 contained onrows31g,31i, and31k, respectively.Sections25b-25fwill have similar configurations, withbus bars67cand67d, bus bars67eand67f, bus bars67gand67h, bus bars67iand67j, and bus bars67kand67lsimilarly disposed onsections25b-25f, respectively. As withsection25ashown in FIG. 7, spark gap switch65 will provide an electrical path viapins66c-66lto bus bars67c-66lsuch that an available charge atbars33a,33c, and33eor bus bars33g,33i, and33k, and thecontacts30 contained onrows31a,31c, and31eor onrows31g,31i, and31kof eachsection25b-f, respectively, will be available. This arrangement will increase efficiency while adopting the other aspects of the invention as previously disclosed.

Though compost materials are envisioned in the preferred method of using the present invention, this system may detect conductive contaminants in any unconsolidated non-conductive material. For example, the present invention may be used in cereals, sugars, or similar foodstuffs or unconsolidated materials to find any conductive contaminant. Additionally, reducing the voltage to prevent false detection due to the conductive nature of unconsolidated materials containing significant amounts of moisture may accommodate unconsolidated materials comprising a moisture-rich content. In those situations, the current transformer must be adjusted such that the sensitivity will accommodate for the lessened voltage as discussed above.

In normal use, less than about four “positive” readings for contaminants for every two hours are expected. In the event that unconsolidated materials contain more conductive contaminants, this frequency will rise and the number of detections will rise accordingly. Moreover, the variable speed ofdetection wheel15, thetransformers46b-46dor62, the voltage, and the sensitivity ofcurrent transformer45, if present, represent the significant variables in the detection system. In typical usage, approximately 100 to 125 yards of unconsolidated material may be processed using the preferred embodiment of the invention. Though any conductive contaminant should be identifiable, the present system has been tested with contaminants comprising copper, aluminum, steel, stainless steel, and foil paper.

Although the present invention and its advantages have been described in considerable detail, it should be understood that various changes, substitutions, and alterations could be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (24)

What is claimed is:

1. A system for detecting at least one conductive contaminant in unconsolidated materials comprising:

at least one nonconductive section, wherein each section has an exterior surface and an interior surface, wherein a plurality of contacts, identified as first contacts or second contacts, are secured or disposed through the section such that at least 1.5 inches (3.8 cm) of each of the contacts extends above the exterior surface of one of the sections;

an uncompleted electrical circuit comprising:

at least one power source wherein each first contact is electrically connected to one power source; and

at least one sensor wherein each second contact is electrically connected to at least one sensor and wherein at least one sensor is electrically connected to each power source; and

wherein each contaminant in unconsolidated materials may be disposed within ¼ inch (0.64 cm) of one of the first contacts and within ¼ inch (0.64 cm) of one of the second contacts, thereby completing the circuit and activating at least one sensor.

2. The system ofclaim 1 further comprising a first conveyor capable of forwarding the materials possibly comprising at least one contaminant onto or near one of the first contacts and onto or near one of the second contacts.

3. The system ofclaim 2 further comprising at least one hopper capable of guiding the materials such that each contaminant falls onto or near one of the first contacts and onto or near one of the second contacts.

4. The system ofclaim 1 wherein each power source comprises at least one transformer.

5. The system ofclaim 1 wherein the sensor comprises an emission source that emits an emission detectable by at least one emission detector that signals at least one relay.

6. The system ofclaim 1 wherein the sensor comprises at least one current transformer.

7. The system ofclaim 1 wherein each sensor is electrically connected to at least one relay system that will stop each conveyor.

8. The system ofclaim 1 further comprising:

a shaft rotatably attached to a frame;

at least one support disk wherein each disk has an outer rim fixedly attached to the shaft wherein each section is fixedly attached or secured to the outer rim of each disk; and

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed between and provides the electrical connection between at least some of the first contacts and at least one power source and wherein the second ring is disposed between and provides the electrical connection between at least some of the second contacts and ar least one sensor.

9. The system ofclaim 1 wherein each first contact is electrically connected to the other first contacts by at least one bus bar disposed on or secured to at least one interior surface of at least one section such that each bar is electrically connected to the first ring via at least one conductive brush.

10. The system ofclaim 1 further comprising:

a shaft rotatably attached to a frame;

at least two support disks, each having an outer rim fixedly attached to the shaft, wherein a plurality of sections are fixedly attached or secured to the outer rim of each disk to form a detection wheel about the shaft;

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed in between and provides the electrical connection to at least some of the first contacts and at least one power source and the second ring is disposed in between and provides the electrical connection to at least some of the second contacts and at least one sensor; and

at least one bus bar connecting each first contact to the other first contacts disposed on the interior surface of each section such that each bar is electrically connected to the first ring via at least one conductive brush.

11. The system ofclaim 10 further comprising:

at least one conveyor capable of forwarding the materials to the exterior surface of at least one section;

at least one hopper capable of guiding the materials leaving the conveyor such that the materials are guided onto the exterior surface of at least one section; and

at least one sensor electrically connected to at least one relay system that will stop each conveyor.

12. The system ofclaim 11 further comprising a second conveyor disposed below the wheel such that the second conveyor may move reviewed materials from the system.

13. The system ofclaim 10 comprising an air manifold attached to the frame and positioned such that the manifold may force air at the contacts extending from the exterior surface of a section facing the second conveyor such that material or contaminants disposed within the contacts will be dislodged.

14. The system ofclaim 10 further comprising a wiper disposed about the second conveyer capable of sweeping the materials and contaminants from the second conveyor.

15. The system ofclaim 10 wherein the system comprises six sections.

16. A system for detecting conductive contaminants in unconsolidated materials comprising:

at least one nonconductive section, having an exterior surface and an interior surface, wherein a plurality of contacts, identified as first or second contacts, are secured or disposed through the section such that at least 1.5 inches (3.8 cm) of each contact extends above the exterior surface;

an uncompleted electrical circuit comprising:

at least one power source electrically connected to the first contacts;

at least one voltage sensor electrically connected to each power source and to the second contacts;

at least one conveyor capable of forwarding the materials to the exterior surface;

at least one hopper capable of guiding the materials leaving the conveyor such that the materials are guided onto the exterior surface;

at least one relay system electrically connected to each sensor that will stop each conveyor;

a shaft rotatably attached to a frame;

at least two support disks, each having an outer rim fixedly attached to the shaft, wherein a plurality of setions are fixedly attached or secured to the outer rim of each disk to form a detection wheel about the shaft; and

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed in between and provides the electrical connection between at least some of the first contacts and at least one power source and the second ring is disposed in between and provides the electrical connection between at least some of the second contacts and at least one sensor;

wherein a conductive contaminant in unconsolidated materials will complete the electrical circuit and activate at least one voltage sensor.

17. The system ofclaim 16 further comprising a second conveyor disposed below the wheel such that the second conveyor may move reviewed materials from the system;

an air manifold attached to the frame and positioned such that the manifold may force air at the contacts extending from the exterior surface of a section facing the second conveyor such that material or contaminants disposed within the contacts will be dislodged; and

a wiper disposed about the second conveyer capable of sweeping the materials and contaminants from the second conveyor.

18. The system ofclaim 16 further comprising a rotating spark gap switch that periodically connects each first contact and each power source wherein the switch provides a potential voltage to selected rows of the first contacts such that all first contacts are provided with the potential voltage at cyclical intervals such that the conductive contaminant disposed within the material will complete the electrical circuit while disposed on the detection wheel.

19. The system ofclaim 18 wherein the switch is rotated by a motor at about 360 rotations per minute such that each first contact receives the potential voltage about 3.6 times per second.

20. The system ofclaim 16 wherein at least one voltage sensor is electrically connected to an input terminal of at least one transformer.

21. A method of detecting conductive contaminants in unconsolidated materials comprising:

allowing the materials to pour into a hopper that guides the materials onto a rotating detection wheel wherein the wheel comprises:

a plurality of nonconductive sections, having exterior surfaces and interior surfaces, wherein a plurality of contacts, identified as first or second contacts, are secured or disposed through each section such that a distance of no more than ¾ inches (1.9 cm) exists between each first contact and a second contact and at least 1 inch (2.54 cm) of each contact extends above the exterior surface of one of the sections;

an uncompleted electrical circuit comprising:

at least one power source electrically connected to the first contacts;

at least one sensor electrically connected to each power source and

to the second contacts; and

a shaft rotably attached to a frame;

at least two support disks, each having an outer rim fixedly attached to the shaft, wherein each section is fixedly attached or secured to the outer rim of each disk to form the wheel about the shaft;

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed in between and provides the electrical connection between at least some of the first contacts and at least one power source and the second ring is disposed in between and provides the electrical connection between at least some of the second contacts and at least one sensor;

wherein a conductive contaminant in unconsolidated materials will complete the electrical circuit activating at least one sensor;

stopping the first conveyor and a second conveyor disposed below the wheel;

wiping the materials from the second conveyor after a delay sufficient to allow the rotating wheel to dump the materials containing the conductive contaminant onto the second conveyor; and

reactivating both the first and second conveyors to process additional materials.

22. The method ofclaim 21 further comprising dislodging any materials or conductive contaminants disposed within that fail to drop onto the second conveyor by blowing air at the contacts extending from the exterior surface of a section facing the second conveyor such that material or contaminants disposed within the contacts fall onto the second conveyor.

23. The method ofclaim 22 further comprising packaging the reviewed unconsolidated material.

24. The method ofclaim 22 further comprising storing the reviewed unconsolidated material.

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